CVE-2026-62959
HIGHCoturn: Pre-authentication heap memory disclosure in ACME redirect (`try_acme_redirect`)
Title source: cnaDescription
Coturn is a free open source implementation of TURN and STUN Server. From 4.5.2 through 4.14.0, when Coturn is started with --acme-redirect <URL> and exposes a plaintext-TCP listener, an unauthenticated remote client can send a single ordinary HTTP GET request and receive a 301 response whose Location header contains up to ~870 bytes of adjacent process heap memory. The leaked region is a recycled network receive buffer that is reused without being zeroed, so on a busy server it can contain data from other clients' requests (TURN credentials, OAuth tokens, relayed payloads). Root cause is a signed→unsigned conversion. This issue is fixed in version 4.15.0.
References (4)
Core 4
Core References
X_Refsource_Confirm x_refsource_confirm
https://github.com/coturn/coturn/security/advisories/GHSA-m23x-5qf5-988g
X_Refsource_Misc x_refsource_misc
https://github.com/coturn/coturn/pull/1965
X_Refsource_Misc x_refsource_misc
https://github.com/coturn/coturn/commit/960835886692fa04cf63ddd970c3f330740c87f4
X_Refsource_Misc x_refsource_misc
https://github.com/coturn/coturn/releases/tag/4.15.0
Scores
CVSS v4
8.2
EPSS
0.0038
EPSS Percentile
31.3%
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-125
CWE-195
Status
published
Products (1)
coturn/coturn
>= 4.5.2, < 4.15.0
Published
Jul 31, 2026
Tracked Since
Aug 01, 2026